1. Field of the Invention
The present invention relates to a relay device.
2. Description of Related Art
A conventional relay circuit includes a plurality of relays which are electrically connected to each other, and is generally manufactured by preparing a wiring board on which a predetermined wiring is provided and to which a plurality of sockets for relays are secured, and fitting relays into respective sockets secured to the wiring board. Otherwise, such a conventional relay circuit may be manufactured by directly securing external connection terminals (contact terminals, coil terminals) to the wiring provided on the wiring board by soldering or the like method without using sockets.
As is well known, the conventional relay includes contact members composed of a movable contact member and a fixed contact member, a magnetic path member which generates magnetic force for driving the movable contact member, a coil which forms magnetic flux for driving the movable contact member in the magnetic path member, an electrically insulating stem for finally supporting the contact members, the magnetic path member, and the coil, and a wiring member (wiring member inside relay) which is formed integrally with the stem, and is electrically connected to both ends of the coil and the contact member with ends thereof serving as external connection terminals for connection with the outside.
In the conventional wiring board for relay circuit, normally, an electric current flowing through contacts of a relay is relatively large, as compared to that of a transistor, and accordingly, cables are normally wired along a rear surface (will be also referred to as an unpackaged surface) of the wiring board. As the coil current is relatively small, conductive patterns which are pattered on the wiring board may be also used.
Publication of Japanese unexamined patent application No. 2000-164098 which has been filed by the present applicant and is now pending proposes a relay in which a wiring member (wiring member inside relay) is formed integrally with a stem by so-called lead frame technique. However, in the above-described conventional relay device, there are many parts and many electrical connections between these parts, and the manufacturing process is complex so that it is difficult to reduce the manufacturing costs greatly.
Publication of Japanese unexamined patent application No. 2000-253539 proposes to form a fixed contact member of a relay by bending one part of a lead frame-like wiring member, and to arrange a plurality of relays on a common base plate which includes this wiring member. This relay device has adopted the arrangement that movable members of a relay unit move in the direction at right angles to a flat main surface of the common base plate, on which the relay unit is packaged, and accordingly, has the problem that the mechanical adjustment of the relay is very difficult after assembling thereof. Namely, in this relay device, the fixed contact member is composed of the wiring member on the common base plate, and accordingly, upon manufacturing the relay unit, it is impossible to perform the final mechanical adjustment of a gap between the fixed contact member and a movable contact member, or the like. Such mechanical adjustment must be performed after assembling the relay unit on the common base plate. This conventional relay device, however, has adopted the arrangement that the moving direction of the movable members such as the movable contact member is directed at right angles to the parts-packaged surface of the common base plate, and accordingly, when a jig (gauge) or the like is inserted into the above-described gap for the mechanical adjustment thereof, it must be inserted in oblique directions. In this case, other members may obstruct the insertion of the gauge to make the insertion work difficult. In addition, these obstructive members must be arranged in the positions spaced from the above-described gap, and accordingly, the overall device becomes undesirably great. These problems become remarkable where a plurality of relays are arranged on the common base plate. In particular, when a plurality of relays are arranged in one direction to make the directions in which the gauges are inserted for adjustment identical to each other, a wide idle space must be provided between adjacent relays for preventing the gauge inserted in an oblique direction from contacting other members.
Published Japanese Translation Publication (KOHYO) No. 10-505191 of PCT International Publication (No. WO96/08023) for Patent Application proposes to weld a fixed contact member of a relay, of which properties have been adjusted, to a bending projection of a wiring member, which projects from a common base plate. With the lead frame-type assembly relay device disclosed in this publication, a completed relay is mounted, and accordingly, the above-described mechanical adjustment (adjustment of contact gap) after assembling the relay is not required. In addition, the moving direction of a movable iron piece is determined at right angles to the surface of the common base plate, similarly to publication of Japanese unexamined patent application No. 2000-253539. Accordingly, the device of this publication has many parts and many electrical connections therebetween. With this arrangement, it is difficult to reduce the manufacturing costs further by making the manufacturing process simple.
It is an object of the present invention to provide a relay device capable of reducing the number of parts and the number of electrical connections between these parts, and making the manufacturing and adjusting works simple, thereby reducing the manufacturing costs thereof.
The relay device in accordance with the present invention will be explained.
The relay device in accordance with the present invention is characterized in that in a relay device which has a plurality of electromagnetic relays, each electromagnetic relay including contact members which are composed of a movable contact member and a fixed contact member, a magnetic path member which generates magnetic force for driving the movable contact member, a coil which forms magnetic flux for driving the movable contact member in the magnetic path member, an electrically insulating stem for finally supporting the contact member, the magnetic path member and the coil, and a wiring member which is formed integrally with the stem, and is electrically connected to both ends of the coil and the contact member with an end of at least one part of the wiring member serving as an external connection terminal for connection with the outside, stems of the plurality of electromagnetic relays are made integral with each other, and are composed of a common base plate which is made integral with the wiring member by resin-molding.
With the relay device in accordance with the present invention, the stems of the electromagnetic relays are made integral with each other. And accordingly, the stems, each being integrally formed with each wiring member by resin molding method or the like, can be manufactured by one molding work. Accordingly, the resin molding process can be greatly shortened, and the number of parts therefor can be reduced. And where other parts of the electromagnetic relays are mounted on the common base plate with which the stems are integrally formed, the packaged position thereof can be determined in designed positions on the common base plate with only one positioning work. Accordingly, the packaging work becomes easy. In addition, the connection of the external connection terminals provided on the common base plate with an external wiring can be performed by one connection work, and accordingly, the wiring work can be performed with ease. Furthermore, by merely securing this common base plate, the mounting work of each electromagnetic relay is completed, and accordingly, the electromagnetic relays can be mounted with ease.
In a preferred embodiment, the wiring member includes a terminal for fixed contact, which projects from the surface of the common base plate, on which parts are packaged, and act as the above-described fixed contact member. With this arrangement, an end of the wiring member of the common base plate serves as the fixed contact member, and accordingly, the connection of the fixed contact member and the wiring member, which has been conventionally required, can be omitted. Consequently, the number of parts and the connecting work decrease to make the manufacturing process simple, and improve the reliability of the relay device.
In another preferred embodiment, the terminal for fixed contact projects from the surface of the common base plate on which the electromagnetic relays are packaged, at approximately right angles thereto, and the movable contact member is secured to the terminal defined by an end of the wiring member, which projects from the surface of the common base plate, so as to contact and separate from the terminal for fixed contact. With this arrangement, the terminal for fixed contact, which acts as the fixed contact member, projects from the surface of the common base plate, on which the electromagnetic relays are packaged, at approximately right angles thereto. In addition, with this arrangement, the terminal for fixed contact, which is defined by the end of the wiring member, can be provided so as to stand approximately upright on the common base plate, and accordingly, the end of the wiring member which extends in parallel with the above-described surface of the common base plate can be readily formed into the fixed contact member, and the wiring member can be readily connected to the movable contact member, and a die for molding the common base plate can be readily manufactured. The bending work of the ends of the wiring member, which is used as the fixed contact member or the terminal for movable contact, may be performed by blanking a metal plate upon preparing the wiring member or thereafter. Otherwise, such bending work may be performed after resin molding of the common base plate.
In still another preferred embodiment, the coil and the magnetic path member are finally supported by the movable contact member. With this arrangement, the assembling of relays (except for the connection of the coil and the wiring member) can be completed by merely securing and connecting the movable contact member on which the coil and the magnetic path member have been previously mounted, to the wiring member (for connection with the movable contact member), which projects from the packaged surface of the common base plate, that is the common stem, by welding, or the like. Accordingly, the work for assembling relays can be made simple. The positioning of the coil and the magnetic path member on the common base plate can be omitted.
In a further preferred embodiment, the movable contact member includes a movable iron piece which is disposed so as to move in a direction approximately parallel with the above-described packaged surface of the common base plate. With this arrangement, the adjustment of the contact gap, or the like can be facilitated.
The mechanical adjustments of the relay properties such as the adjustment of a contact gap, which are to be performed after mounting of the electromagnetic relay unit on the common base plate, can be effected with ease. For example, gauges can be inserted into corresponding parts of the electromagnetic relay unit for the above-described adjustments, and accordingly, the adjustment work becomes easy. In addition, working spaces which conventionally have been required for the adjustments of the relay properties, can be omitted, and accordingly, the device can be made compact.
In preferred embodiments, the electromagnetic relay units are arranged in a line on the packaged surface of the common base plate. With this arrangement, the direction of the mechanical adjustment of the electromagnetic relay units can be made identical to each other, and accordingly, the mechanical adjusting operation can be made simple, and the above-described working space is not required to provide between electromagnetic relay units. Therefore, the device can be made small and light, and the length of a common wiring part between electromagnetic relay units can be made short.
Other objects, features, and characteristics of the present invention will become apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification.